The angular dispersion of a prism depends on

The angle of incidence as well as the index of refraction

The thickness of the prism only

Ripple in a power supply unit is caused by

using an alternating current source

The mass of a nucleus is the

total number of its proton and neutrons

total number of its protons and electrons

A body was slightly displaced from its equilibrium position. Which one of the following is a condition for its stable equilibrium

an increase in the potential energy of the body

an increase in the kinetic energy of the body

an increase in the potential energy of the body

an increase in the height of the body

Which of these is observed when air is pumped out of a discharge tube without lowering its pressure

the conductivity of the air increases

the conductivity of the air decreases

JAMB UTME - Physics - 2019 | Green Bridge CBT

Question 1 Report

According to kinetic molecular model, in gases

The molecules are very fast apart and occupy all the space made available.

The particles occur in clusters with molecules slightly farther apart.

The particles are closely packed together, they occupy minimum space and are usually arranged in a regular pattern.

The particles vibrate about fixed positions and are held together by the strong inter-molecular bond between them.

Answer Details

In kinetic molecular model, gases are energised and thus moves freely, fast as they occupy specific space

Read lesson note on Gas Laws (JAMB)

Read lesson note on Quantity Of Heat (JAMB)

Read lesson note on Thermal Expansion (JAMB)

Read lesson note on Structure Of Matter And Kinetic Theory (JAMB)

Gas Laws

Quantity Of Heat

Thermal Expansion

Structure Of Matter And Kinetic Theory

View Answer

Question 2 Report

Electrons were discovered by

Dalton

James Charwick

J.J. Thompson

Niels Bohr

Answer Details

Electrons were discovered by J.J. Thompson. In the late 19th century, he performed a series of experiments using cathode ray tubes, which are glass tubes containing low-pressure gas and electrodes. By applying high voltage, he observed a beam of negatively charged particles traveling from the negative electrode to the positive electrode. He concluded that these particles, which he called "corpuscles," were fundamental units of negative charge and later were renamed electrons. This discovery led to the development of the modern understanding of atomic structure and the electron's role in it.

Read lesson note on Structure Of The Atom (Nigeria Only) (WAEC)

Structure Of The Atom (Nigeria Only)

View Answer

Question 3 Report

Which of the following media allow the transmission of sound waves through them?

I. air

II. liquid

III. solids

I and II only

I and III only

II and III only

I, II and III

Answer Details

Sound waves are disturbances in a medium that propagate through the medium and transfer energy from one point to another. The transmission of sound waves depends on the physical properties of the medium, including its elasticity and density. Air (Option I) is a gas that is compressible and has a relatively low density, which makes it an excellent medium for transmitting sound waves. Liquids (Option II) are also able to transmit sound waves, although the speed of sound in liquids is slower than in gases because liquids are more dense and less compressible. Solids (Option III) are able to transmit sound waves as well, but their density and elasticity make them more rigid, which means that sound waves in solids tend to be transmitted as elastic waves or mechanical waves, rather than as acoustic waves. Therefore, the correct answer is "I, II, and III".

Read lesson note on Sound Waves (WAEC)

Sound Waves

View Answer

Question 4 Report

When a girl moves towards a plane mirror at a speed of 4.0m/s, the distance between the girl and her image reduces a speed of

2 m/s

4 m/s

8 m/s

12 m/s

Answer Details

v

=

dt

or

v

α

d

d = x, v = 4m/s
d = 2x, v = ? (girl and image)

v

=

2 × 4x

=

8

ms

Read lesson note on Reflection Of Light At Plane And Curved Surfaces (JAMB)

Reflection Of Light At Plane And Curved Surfaces

View Answer

Question 5 Report

The distance between an object and its real image in a convex lens is 40cm. If the magnification of the image is 3, calculate the focal length of the lens

6.5 cm

7.5 cm

8.5 cm

4.5 cm

Answer Details

u + v = 40

$\frac{v}{u}$ = 3

v = 3u

u + 3u = 40

4u = 40

u = 10cm

v = 3u = 30cm

f = $\frac{u v}{u + v} = \frac{10 (30)}{10 + 30} = \frac{300}{40}$

= 7.5 cm

Read lesson note on Gravitational Field (WAEC)

Gravitational Field

View Answer

Question 6 Report

In a slide wire bridge, the balance is obtained at a point 25cm from one end of wire 1m long. The resistance to be tested is connected to that end and a standard resistance of $3.6\,\Omega$ is connected to the other end of the wire. Determine the value of the unknown resistance

3.2

Ω

1.4

Ω

3.21

Ω

1.2

Ω

Answer Details

$\frac{R}{3.6} = \frac{75}{25} = \frac{1}{3}$

3R = 3.6

R = 1.2 $Ω$

View Answer

Question 7 Report

When the temperature of a liquid is increased, its surface tension

increases

decreases

remain constant

increases then decreases

Answer Details

Surface tension or elasticity of a fluid decreases with increased in temperature

Read lesson note on Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

View Answer

Question 8 Report

The value of T in the figure above is

30N

10.0N

20N

40N

Answer Details

Tsin30 + Tsin30 =40

2Tsin30 = 40

Tsin30 = 40/2 = 20

T( $\frac{1}{2}$ ) = 20

T = 20 x 2 = 40N

Read lesson note on Scalars And Vectors (JAMB)

Read lesson note on Motion (JAMB)

Scalars And Vectors

Motion

View Answer

Question 9 Report

The momentum of a car moving at a constant speed in a circular track

can be both positive and negative

can be zero depending on its position in the track

a centrifugal

Answer Details

Movement of an object in a circle with an acceleration towards its center is provided by change in velocity and centripetal force a α V α Fc

Read lesson note on Motion (JAMB)

Motion

View Answer

Question 10 Report

The resultant capacitance in the figure above is

0.4μf

0.8μf

1.8μf

4.5μf

Answer Details

For the parallel arrangement = 2 + 4 = 6μf

For

the

series

arrangement

=

1C

_{T}

=

12

+

13

+

16

+

14

1C

_{T}

=

1512

C

_{T}

=

1215

=

0.8μf

Read lesson note on Capacitors (JAMB)

Capacitors

View Answer

Question 11 Report

The pitch of a screw jack is 0.45cm and the arm is 60cm long. If the efficiency of the Jack is 75/π %, calculate the mechanical advantage.

400

300

200

150

Answer Details

P = 0.45cm, L = 60cm, Eff = 75/π%

VR

(Screw

system)

=

2πrP

=

2πLP

M.A

=

Eff% × VR100

=

75π

×

1100

×

2π × 600.45

=

75 × 800300

=

200

Read lesson note on Simple Machines (JAMB)

Read lesson note on Measurements And Units (JAMB)

Simple Machines

Measurements And Units

View Answer

Question 12 Report

Efficiency of conduction in liquids and gases compared to solids is

less efficient than solid

more efficient than solids

equally efficient to solids

efficiently may vary

Answer Details

The efficiency of conduction in liquids and gases compared to solids is generally less efficient. This means that solids are better conductors of heat and electricity than liquids and gases. This is because the particles in solids are closely packed and are tightly bound to one another, allowing heat and electricity to flow easily through the material. On the other hand, the particles in liquids and gases are more spread out and less tightly bound, making it more difficult for heat and electricity to flow through these materials. However, it is important to note that the efficiency of conduction can vary depending on the specific liquid or gas and the specific solid being compared. Some liquids and gases may have properties that make them better conductors than certain solids, but this is not a general rule.

View Answer

Question 13 Report

A ray of light passes through the centre of curvature of a concave mirror and strikes the mirror. At what angle is the ray reflected?

180

^{o}

90

^{o}

0

^{o}

60

^{o}

Answer Details

When a light ray passes through the center of curvature of a concave mirror and strikes the mirror, the reflected ray will be reflected back on itself, creating an angle of 0 degrees. Therefore, the correct answer is 0o.

View Answer

Question 14 Report

The diagram above represents the stress-strain graph of a loaded wire. Which of these statements is correct?

At J, the wire becomes plastic

J is the yield point

L is the elastic limit

At K, the wire breaks

Answer Details

- I is the elastic limit
- the end of the constant part J is the yield point
- L is the break point.

Read lesson note on Elasticity (JAMB)

Read lesson note on Measurements And Units (JAMB)

Elasticity

Measurements And Units

View Answer

Question 15 Report

The Earth's magnetic equator passes through Jos in Nigeria. At Jos, the

angle of variation is zero

magnetic declination is 90

angle of dip is zero

horizontal component at the Earth's field is zero

Answer Details

The Earth has a magnetic field that is generated by the movement of molten iron in its core. The magnetic field has different properties at different locations on the Earth's surface. The magnetic equator is an imaginary line on the Earth's surface where the inclination or tilt of the Earth's magnetic field is zero, meaning that the magnetic field lines are parallel to the Earth's surface. At Jos, Nigeria, the Earth's magnetic equator passes through, which means that the angle of inclination or dip of the Earth's magnetic field is zero. Therefore, the correct answer is that the angle of dip is zero. This means that a magnetic needle suspended by a thread or placed on a horizontal surface would remain horizontal and not point downwards or upwards, as it would at other locations on the Earth's surface. This makes Jos an important location for studying the Earth's magnetic field and for conducting experiments related to magnetism.

Read lesson note on Electromagnetic Field (Part 2) (WAEC)

Electromagnetic Field (Part 2)

View Answer

Question 16 Report

If a body moves with a constant speed and at the same time undergoes an acceleration, its motion is said to be

oscillation

circular

rotational

rectilinear

Answer Details

If a body moves with a constant speed but at the same time undergoes an acceleration, its motion is called rectilinear motion. This means that the body moves in a straight line and its speed changes at a constant rate, causing an acceleration. It is different from oscillation, circular and rotational motions which involve changes in direction, as well as changes in speed.

Read lesson note on Rectilinear Acceleration (WAEC)

Rectilinear Acceleration

View Answer

Question 17 Report

Three resistors with resistance 200Ω, 500Ω and 1kΩ are connected in series. A 6v battery is connected to either end of the combination. Calculate the potential difference between the ends of 200Ω resistance.

0.71V

0.7V

0.82V

0.8V

Answer Details

To calculate the potential difference between the ends of the 200Ω resistance, we need to use Ohm's Law, which states that the potential difference (V) across a resistor is equal to the current (I) flowing through the resistor multiplied by the resistance (R) of the resistor. First, we need to find the total resistance of the series combination of resistors. We add up the individual resistances: Total resistance = 200Ω + 500Ω + 1kΩ = 1.7kΩ Next, we can use Ohm's Law to find the current flowing through the circuit. We know that the battery voltage is 6V, and the total resistance is 1.7kΩ: I = V / R = 6V / 1.7kΩ = 0.0035A Now we can use Ohm's Law again to find the potential difference across the 200Ω resistor: V = IR = 0.0035A * 200Ω = 0.7V Therefore, the potential difference between the ends of the 200Ω resistance is 0.7V. The correct answer is option B.

Read lesson note on Current Electricity (JAMB)

Current Electricity

View Answer

Question 18 Report

An alternating current can induce voltage because it has

ripple value

varying magnetic field

weaker magnetic field than direct current

high peak value

Answer Details

An alternating current can induce voltage because it has a varying magnetic field. An alternating current (AC) is an electrical current that periodically reverses direction, unlike direct current (DC), which flows in one direction. When an AC current flows through a wire, it generates a magnetic field that changes direction with the current. As the current alternates, the magnetic field expands and contracts, inducing an electromotive force (EMF) in any nearby conductor or coil of wire. This phenomenon is known as electromagnetic induction, and it is the basis for the operation of many electrical devices, such as generators and transformers. The induced voltage depends on the strength and rate of change of the magnetic field and the number of turns in the coil. In summary, an alternating current can induce voltage because it creates a varying magnetic field, which in turn generates an electromotive force in nearby conductors or coils of wire, according to the principle of electromagnetic induction.

View Answer

Question 19 Report

Gases conduct electricity under

high pressure and high voltage

low pressure and low voltage

normal pressure and low voltage

low pressure and high voltage

Answer Details

Gases conduct electricity under low pressure and high voltage

Read lesson note on Gas Laws (JAMB)

Gas Laws

View Answer

Question 20 Report

The equilibrium position of objects in any field corresponds to situation of

equipotential energy

maximum potential energy

minimum potential energy

maximum kinetic energy

Answer Details

The equilibrium position of an object in any field corresponds to the situation of minimum potential energy. This means that at the equilibrium position, the object has the lowest possible potential energy within the field. In other words, the forces acting on the object are balanced, and the object is not being pushed or pulled in any direction. Therefore, the object will remain at rest at the equilibrium position unless it is acted upon by an external force. Of the options given, the correct answer is "minimum potential energy".

Read lesson note on Gravitational Field (WAEC)

Read lesson note on Measurements And Units (JAMB)

Gravitational Field

Measurements And Units

View Answer

Question 21 Report

During the transformation of matter from the solid to the liquid state, the heat supplied does not produce temperature increase because

all the heat is used to break the bonds holding the molecules of the solid together

the heat capacity has become very large as the substance melts

the heat energy is quickly conducted away

the heat gained is equal to the heat lost by the substance

Answer Details

When a solid is heated to its melting point, the heat supplied is used to overcome the intermolecular forces holding the molecules in a fixed position, resulting in the breaking of these bonds. As a result, the solid transforms into a liquid without any change in temperature. This is because the heat energy supplied is used in breaking the bonds between molecules rather than increasing the kinetic energy of the molecules, which is what causes an increase in temperature. Therefore, the correct option is: "all the heat is used to break the bonds holding the molecules of the solid together."

Read lesson note on Change Of State (JAMB)

Change Of State

View Answer

Question 22 Report

The diagram shows four positions of the bob of a simple pendulum. At which of these positions does the bob have maximum kinetic energy and minimum potential energy

1

2

3

4

Answer Details

At position 1, the bob of the simple pendulum has the maximum potential energy and zero kinetic energy. At position 4, the bob has the maximum kinetic energy and minimum potential energy. To understand this, we need to know that the energy of a simple pendulum is converted back and forth between kinetic energy and potential energy as it swings back and forth. When the bob is at its highest point (position 1), it has the maximum potential energy because it is farthest from the ground and has the most potential to move downward. At this point, the bob has zero kinetic energy because it is momentarily at rest. As the bob swings downward towards the equilibrium point, it gains speed and its potential energy is converted to kinetic energy. At the equilibrium point (position 2), the bob has equal amounts of kinetic and potential energy. As the bob continues to move downward, its potential energy decreases and its kinetic energy increases. At position 3, the bob has minimum potential energy and some amount of kinetic energy. At the lowest point of its swing (position 4), the bob has maximum kinetic energy because it is moving at its fastest speed. At this point, the bob has minimum potential energy because it is closest to the ground and has the least amount of potential to move downward. So, to summarize, the bob has maximum potential energy at position 1, equal amounts of kinetic and potential energy at position 2, minimum potential energy at position 3, and maximum kinetic energy at position 4.

Read lesson note on Newton’s Laws Of Motion (WAEC)

Read lesson note on Equilibrium Of Forces (WAEC)

Newton’s Laws Of Motion

Equilibrium Of Forces

View Answer

Question 23 Report

- angle of dip is zero at the magnetic equator
- angle of variation is the same as angle of declination.

angle of variation is zero

magnetic declination is 90

angle of dip is zero

horizontal component at the Earth's field is zero

Answer Details

- angle of dip is zero at the magnetic equator
- angle of variation is the same as angle of declination.

Read lesson note on Magnetic Field (Part 2) (WAEC)

Read lesson note on Electric Field (WAEC)

Magnetic Field (Part 2)

Electric Field

View Answer

Question 24 Report

In the molecular explanation, heat is transferred by the

free electron

free atoms

free molecules

free solids

Answer Details

- Conduction is explained in terms of the free electrons
- Convection is explained in terms of the movement of the fluid involved
- Radiation is explained in terms of invisible electromagnetic waves.

Read lesson note on Thermal Expansion (JAMB)

Thermal Expansion

View Answer

Question 25 Report

In which of the points labelled A, B, C, D and E on the conductor shown would electric charge tend to concentrate most

A

B

C

E

Answer Details

- Charge are mostly concentrated at the outermost part of a hollow conductor
- Charge are also mostly concentrated at the pointed ends or places with high density point.

Read lesson note on Electric Field (WAEC)

Read lesson note on Electrostatics (JAMB)

Electric Field

Electrostatics

View Answer

Question 26 Report

Which of the following characteristics of a wave is used in the measurement of the depth of the Sea?

diffraction

interference

refraction

reflection

Answer Details

Depth of sea can be measured by echo, a reflected sound waves.

Read lesson note on Properties Of Waves: Reflection, Refraction, Diffraction (WAEC)

Properties Of Waves: Reflection, Refraction, Diffraction

View Answer

Question 27 Report

Radio waves belongs to the class of ware whose velocity is about

340m/s

3 × 10

^{6}

m/s

3 × 10

^{8}

m/s

3 × 10

^{- 8}

m/s

Answer Details

Radio waves belong to the class of waves whose velocity is approximately 3 x 10^8 m/s. This velocity is commonly denoted as the speed of light, which is the speed at which all electromagnetic waves, including radio waves, travel in a vacuum. This constant velocity is one of the fundamental principles of physics and is important in understanding the behavior and properties of light and other electromagnetic waves. The speed of light is incredibly fast, and it's difficult for us to imagine just how fast it is. To put it into perspective, light can travel around the Earth's equator almost 7.5 times in just one second. This high speed is essential for radio communication, as it enables radio waves to travel long distances in a short amount of time, allowing us to communicate with people and devices far away from us.

Read lesson note on Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum (WAEC)

Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum

View Answer

Question 28 Report

The conductivity of gases at low pressure can be termed as

I. hot cathode emission

II. thermo ionic emission

III. cold cathode emission

IV. Field emission

I and II

II and III

III and IV

IV and V

Answer Details

As conduction of gases is at low pressure and high voltage, called field or cold cathode emission.

Read lesson note on Properties Of Waves: Reflection, Refraction, Diffraction (WAEC)

Properties Of Waves: Reflection, Refraction, Diffraction

View Answer

Question 29 Report

The height at which the atmosphere cases to exist is about 80km. If the atmospheric pressure on the ground level is 760mmHg, the pressure at a height of 20km above the ground level is

$(\rho_m = 13.6g/cm^3\ \rho = 0.00013g/cm^3)$

380mmHg

570mmHg

190mmHg

480mmHg

Answer Details

ρ $_{m}$ h $_{m}$ = ρ $_{a}$ h $_{a}$
13.68(760 - p) × 10 $^{- 3}$ = 13 × 10 $^{- 5}$ (20 × 10 $^{3}$ )

760

-

p

=

13 × 10

^{- 5}

× 20 × 10

^{3}

13.68 × 10

^{- 3}

=

19.00

×

10

^{1}

760 - p = 190
p = 760 - 190 = 570mmHg

Read lesson note on Pressure (JAMB)

Pressure

View Answer

Question 30 Report

The limiting frictional force between two surface depends on

I. the normal reaction between the surfaces

II. the area of surface in contact

III. the relative velocity between the surfaces

IV. the nature of the surface

I only

I and IV only

II only

III only

Answer Details

The correct answer is "I and IV only". The limiting frictional force between two surfaces depends on the normal reaction between the surfaces (I) and the nature of the surface (IV). The normal reaction is the force that the surfaces exert on each other perpendicular to the plane of contact. The greater the normal reaction, the greater the frictional force that can be applied before motion occurs. The nature of the surface is determined by factors such as roughness, hardness, and texture, which can affect the frictional force. The area of surface in contact (II) does not directly affect the limiting frictional force, although it can affect the force required to initiate motion. For example, if the area of contact is small, the pressure between the surfaces will be higher, making it harder to initiate motion. The relative velocity between the surfaces (III) also does not directly affect the limiting frictional force, although it can affect the force required to maintain motion. If the surfaces are already in motion, a lower force may be required to keep them moving than to initiate motion. In summary, the limiting frictional force between two surfaces depends primarily on the normal reaction and the nature of the surface, and is not directly affected by the area of contact or the relative velocity between the surfaces.

Read lesson note on Friction (JAMB)

Friction

View Answer

Question 31 Report

The pin-hole camera produces a less sharply defined image when the

pin-hole is larger

illumination is less

screen is further from the pin-hole

object is further from the pin-hole

Answer Details

The pin-hole camera produces a less sharply defined image when the pin-hole is larger. A pin-hole camera works by allowing light to pass through a small hole (the pin-hole) and project an inverted image of the outside world onto a screen or surface located behind the hole. The smaller the pin-hole, the sharper the resulting image, as light passing through a smaller hole produces less diffraction or spreading out of the light. When the pin-hole is larger, more light enters the camera, but the light rays also become more scattered, resulting in a less well-defined image. This is because the larger opening allows more light rays to enter at different angles, creating a wider range of paths that the light can take as it travels through the camera and onto the screen. As a result, the image is less clear and less defined, with less sharp edges and more blurring. is the correct answer because it correctly identifies the effect of a larger pin-hole on the image produced by the pin-hole camera. less illumination, would actually produce a dimmer image, but it would not affect the sharpness or definition of the image. the distance of the screen from the pin-hole, and the distance of the object from the pin-hole, would affect the size of the image and the scale of the objects, but they would not affect the sharpness or definition of the image.

Read lesson note on Light Energy (JAMB)

Read lesson note on Structure Of The Nucleus (WAEC)

Light Energy

Structure Of The Nucleus

View Answer

Question 32 Report

A mixture of blue and red pigment when illuminated by white light will appear

green

orange

purple

magenta

Answer Details

A mixture of blue and red pigment when illuminated by white light will appear purple. This is because when white light shines on a surface, it contains all the colors of the visible spectrum. When blue and red pigments are mixed together, they absorb all the other colors in the spectrum except for blue and red. Therefore, when white light shines on this mixture, the blue pigment absorbs all the colors except blue, while the red pigment absorbs all the colors except red. The result of this is that the blue and red pigments reflect only blue and red light, which then combines to form purple. Therefore, the mixture of blue and red pigments appears purple when illuminated by white light.

Read lesson note on Structure Of The Nucleus (WAEC)

Structure Of The Nucleus

View Answer

Question 33 Report

A rectangular solid black has length 10cm, breadth 5cm and height 2cm. If it lies on a horizontal surface, and has density $100\text{kg/m}^3$, calculate the pressure it exerts on the surface.

200 N/m

^{2}

100 N/m

^{2}

400 N/m

^{2}

Answer Details

To calculate the pressure that the rectangular solid exerts on the surface, we need to use the formula for pressure: Pressure = Force / Area In this case, the force is the weight of the rectangular solid, which we can calculate using the formula: Weight = Mass x Gravity The mass of the rectangular solid can be calculated using its density and volume: Mass = Density x Volume The volume of the rectangular solid is simply its length x breadth x height: Volume = Length x Breadth x Height = 10 cm x 5 cm x 2 cm = 100 cm3 We need to convert this volume to cubic meters to use the density given in kg/m3: Volume = 100 cm3 = 0.0001 m3 Now we can calculate the mass: Mass = Density x Volume = 100 kg/m3 x 0.0001 m3 = 0.01 kg The gravity is the acceleration due to gravity, which we can assume to be 9.81 m/s2. Therefore, the weight is: Weight = Mass x Gravity = 0.01 kg x 9.81 m/s2 = 0.0981 N Now we can use this weight to calculate the pressure on the surface. The surface area in contact with the rectangular solid is simply its length x breadth: Area = Length x Breadth = 10 cm x 5 cm = 50 cm2 We need to convert this area to square meters: Area = 50 cm2 = 0.005 m2 Therefore, the pressure is: Pressure = Force / Area = 0.0981 N / 0.005 m2 = 19.62 N/m2 We can convert this to units of N/cm2 or N/mm2 if desired. This is equivalent to: Pressure = 0.1962 N/cm2 = 0.0001962 N/mm2 So the pressure that the rectangular solid exerts on the surface is 19.62 N/m2, which is approximately 20 N/m2. Therefore, the answer is 200 N/m2.

Read lesson note on Pressure (JAMB)

Read lesson note on Measurements And Units (JAMB)

Pressure

Measurements And Units

View Answer

Question 34 Report

If the time of flight is 96seconds, calculate the horizontal range through the point of projection.

84400m

69000m

61440m

24000m

Answer Details

Time of flight, T = 96s
R = (Ucosθ) *time* T = 640 × 96 = 61,440m

Read lesson note on Motion (JAMB)

Motion

View Answer

Question 35 Report

Water and Kerosine are drawn respectively into the two limbs of a Hare's apparatus. The destiny of water is $1.0\mathrm{g\,cm^{-3}}$ and the density of kerosine is $0.80\mathrm{g\,cm^{-3}}$. If the height of the water column is 20.0cm, calculate the height of the kerosine column.

1.6cm

16.0cm

20.0cm

25.0cm

Answer Details

Devices with different liquids
d $_{1}$ h $_{1}$ = d $_{2}$ h $_{2}$
1 × 20 = 0.8 × h

h

=

200.8

=

25cm

Read lesson note on Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

View Answer

Question 36 Report

A boy pushes a 500kg box along a floor with a force of 2000N. If the velocity of the box is uniform, the co-efficient of friction between the box and the floor is

1

0.8

0.65

0.4

Answer Details

The coefficient of friction is a measure of the amount of friction between two surfaces. It is represented by the symbol "μ" and is a dimensionless quantity. The coefficient of friction between two surfaces depends on the nature of the surfaces in contact and the force pressing them together. In this problem, the boy is pushing the box with a force of 2000N. If the box is moving with a uniform velocity, then the force of friction acting on the box is equal and opposite to the pushing force applied by the boy. We can calculate the force of friction using the formula: frictional force = coefficient of friction x normal force where the normal force is the force exerted by the floor on the box in a direction perpendicular to the floor. Since the box is not moving up or down, the normal force is equal to the weight of the box. The weight of the box can be calculated using the formula: weight = mass x gravity where mass is the mass of the box and gravity is the acceleration due to gravity (9.8 m/s^2). So, the weight of the box is: weight = 500 kg x 9.8 m/s^2 = 4900 N The force of friction is equal to the pushing force of 2000N, so we can set these two equal to each other and solve for the coefficient of friction: frictional force = 2000N coefficient of friction x normal force = 2000N coefficient of friction x 4900N = 2000N coefficient of friction = 2000N / 4900N = 0.408 So, the coefficient of friction between the box and the floor is approximately 0.4. Therefore, the correct answer is 0.4.

Read lesson note on Equilibrium Of Forces (WAEC)

Read lesson note on Measurements And Units (JAMB)

Equilibrium Of Forces

Measurements And Units

View Answer

Question 37 Report

Aluminium is sometimes used as the leaf of an electroscope because it

is a light material

is a good conductor

is a good insulator

can be converted into thin sheets

Answer Details

- Aluminium can be made in thin sheet like Gold.
- the leaf is a thin material that can be diverged easily.

Read lesson note on Electrostatics (JAMB)

Electrostatics

View Answer

Question 38 Report

If a body moves with a constant speed and at the same time undergoes an acceleration, its motion is said to be

circular

oscillatory

rectilinear

rotational

Answer Details

If a body moves with a constant speed and at the same time undergoes an acceleration, its motion is said to be rectilinear. When an object moves with constant speed, it means that it covers the same distance in equal time intervals. On the other hand, acceleration is the rate of change of velocity with time. If an object undergoes acceleration, its velocity changes with time. Therefore, if a body moves with constant speed and undergoes an acceleration, it means that its direction of motion changes while it covers equal distances in equal time intervals. This type of motion is called rectilinear motion, where the object moves in a straight line, but its velocity changes due to the acceleration. In contrast, circular motion is when an object moves in a circular path with a constant speed, while oscillatory motion is when an object moves back and forth around a fixed point. Rotational motion is when an object rotates around an axis. None of these descriptions fit the scenario of a body moving with constant speed and undergoing acceleration, so the answer is rectilinear motion.

Read lesson note on Motion (JAMB)

Motion

View Answer

Question 39 Report

A siren having a ring of 200 hole makes 132 rev/min. A jet of air is directed on the set of holes. Calculate the frequency and wavelength in air of the note produced (take v = 350m/s)

0.875m

0.625m

0.335m

0.125m

Answer Details

n = 200, S = 132 rev/min, v = 350m/s $^{2}$

f

=

ns

=

200

×

132

revmin

×

1min60s

=

440Hz

λ

=

vf

=

350440

=

0.875m

Read lesson note on Quantity Of Heat (JAMB)

Quantity Of Heat

View Answer

Question 40 Report

The following are parts of the eye

I. Retina

II. Pupil

III. Iris

The correct equivalent in the camera in the same order are

Diaphragm, Aperture, film

Aperture, Diaphragm, Film

Film, Diaphragm, Aperture

Film, Aperture, Diaphragm

Answer Details

- retina is similar to film
- pupil is similar to aperture
- iris is similar to diaphragm

Read lesson note on Structure Of The Atom (Nigeria Only) (WAEC)

Structure Of The Atom (Nigeria Only)

View Answer






Press & Hold to Drag Around
Click Here to Close